Screening device



P 5. J. GILSON 3 83 SCREENING DEVICE Filed Oct. 14, 1940 2 Sheets-Sheetl Patented Sept. 19, 1 944 UNITED STATES PATENT OFFICE s CREENING DEVICESeth J. Gilson, Mercer, Pa., assignor to Heath Smith, Mercer, Pa.

ApplicationOctober 14, .1940, Serial No. 361,150

10 Claims. (01. 299-319) My invention relatesto a screening device forcrushed stone, gravel, sIag sand and similar materials. It isparticularly useful for testing samples of such materials, which itaccomplishes in a highly efficient manner, the tests being speedy andextremely accurate as to the sizes and proportions of the constituentparts of the material tested, while the operations necessary to thetests are simple and easy to perform, and many operations heretoforenecessary in prior testing devices are eliminated.

Inits more specific aspect my invention contemplates thev use ofscreening instrumentalities comprising a series of screen trays tightlybound together for operation as a'single rigid unit, which unit,preferably, is freely suspended vertically from the main stationarysupporting frame, the suspension being preferably cushioned bysupporting springsbetween the main frame andthe unit whereby vibrationof the fixed. or supporting frame is minimized and substantiallyeliminated, the spring. connections .serving as shock absorbers. Theunit is preferably centered top and bottom, conveniently by rodsattached thereto, which also may constitutethemeans for binding itsparts together, said rods advantageously extending through bushings inthe top and bottom of the fixed frame to insure vertical reciprocationof the unit. In order to maintain the susv pension characteristic of theunit, the driving mechanism. for reciprocating it is preferably,

mountedon top of the fixed frame and connected to the unit by verticallysuspended links, which:

are reciprocated by cams operated by said driving. mechanism. Thislocation of the drive mechanism further permits the trays to occupy alowerposition. Where they aremoreaccessibletothe.

operator. When the fixed frame is properly leveled, vertical operationis assured. By reason of the compactness and freedom from externalvibration. of my structure, it is possible to operate the. screens-atamuch i herspeed than similar devices of the prior art, and this higherspeed enables me to employ a shorter amplitude of vibration of the unit.r

A. most. important aspect of. my invention is the construction-of. theoscillating unit whereby the screen trays. therein may be tightly boundtogether for the screening operation, yet by sim-- ple loosening of thebinding mechanism any single tray may be independently removed and alsoanyone or more of the plurality of trays: may be left outflif thecharacter of. thetests being made" do ,not, require theiruse. These;operations-may be simply accomplished by a system of spacers andaccessory parts devised by me. Each tray compartment in' the unit ispreferably tightly sealed on two sides and-the rearagainst escape of anymaterial therefrom, while at the front an open space is provided forinspection of the operation as itproceeds. Each tray, when empty,isbalanced to Weigh the same as each other tray, balancing weights beingapplied, as necessary, to the individual trays to effect this. result.This permits a single reading of thescale to determine the weight of thecontents of any giventray.

A further important feature of my invention is the location of the dustpanin a fixed position below the reciprocating-frame; wherebyit re'-'mains stationary, whereas in priorconstructions it was mounted as partofthe movable tray unit. All of the moving parts are contained within theouter or main frame, which is so constructed as to avoid contact by theoperator with moving parts and therebythe highest degree -of safety tothe operator is insured. Y

Further features and advantages of tion will hereinafter appear. c

The accompanying drawingsshow for purpose my invenof exemplification,but without limiting my in-' preferred embodiments spective view of aspacer member employed insaid unit; Fig. 3 is a front elevation partlyinsection showing features of my driving mechanism for oscillating saidunit; Fig. 4; is a transverse vertical section onthe line 44 in Fig; 1;and Fig. 5 is a transverse vertical section of one of the trays. I v IReferringto thedr'awings, there is shown (Figs.

land 4) .a stationary framel having suspended for vertical reciprocationtherein a rigid tray unit 2 and driving mechanism 3. for said unit.

The stationary frame I is preferably closed on its two sides and rear,while open at the front to permit access to the interior ofthe. casingand,

inspection of the trays. V

The reciprocating tray unit- 2 comprises an upper rectangular framemember 5' preferably made of, angle iron and a similar lower framemember 6, the latterbeing open at its front end, its free front endsbeing tied together by an inverted U-shaped tie member 1; locatedbetween the upper and lower frame members 5 and Bare aseries of U-shapedspacers 8 outwardly flanged at their upper and lower ends. Said upperand.

lower frame members and spacers are bound together to form thereciprocating unit by tightening rods 9 passing freely through openingsH in the internal flanges H] at the top of the main casing andpreferably through recesses or openings l2 midway the side flanges ofthe spacers 8, said rods being provided with screw threads at theirlower ends on which are mounted nuts [3 rigidly attached as by weldingto the underside of the lower frame member 6, said. rods being providedat their upper ends with stop collars l4 rigidly attached thereto as bywelding, which are of a size sufficiently small to permit their beingintroduced with the rods through the opening H in the flange II), butsufiiciently large to prevent them passing through the opening in theupper frame member 5 through which the rods pass. In order to insuretrue vertical reciprocation of the reciprocating unit, a bearing memberl5 (placed on said rods above the collars I4 before the latter arewelded to the rods) are secured to the tops of the internal flanges In,over the openings II, and a similar bearing I6 is secured to theunderside of the U-shalped lower frame member I! made of angles iron,which reinforces the bottom of themain stationary frame I. The bearingmember 16 islof a size to fit the lower reduced ends H? of said rods.Said rods are provided at their top ends with means for turning the samein'theibearings, suchmeans being herein the unit, and one on each sidenear the front, their positions being more clearly indicated by thepositions of the corresponding flange openings in the spacer flanges inFig. 2. Any

variation in the number or location of these spacer rods, which willinsure adequate support for the spacers, may, of course, be employed.

When the trays have been slid into their respective positions, withtheir flanges between the flanges of the spacers and top frame member,the crank members I9 are turned to raise the bottom frame member 6upwardly and bind the flanges of the trays, spacers and upper framemember thereby relaxing the clamping action on each shown as crankextensions [9 formed on. the 1 upper ends of the rods. The reciprocatingunit 2 is designed to carry a plurality of screen trays 20, eachprovided with. appropriate screen mesh bottom 2|. These trays areprovided at their upper ends with outwardly extending flanges 22,saidtrays being of less depth than said spacers 8, and each traybeing'adapted to be slid into the reciprocating unit 2, its flange 22passing between the upper flange on a spacer and the lower flange of thespacer immediately above said first mentioned spacer. The flanges of thetop tray are similarly adapted to lie between the horizontal flange oftheupper frame member 5 and the upper flanges of the uppermost spacermember 8. A stationary dust pan 29a is suptray flange and permitting anyindividual tray to be'removed independently of any other tray.

The reciprocating unit 2 as a whole is resiliently mounted as asuspension member in the main frame by means of suspension rods 28,preferably located at each corner of the stationary frame and attachedthereto' at their upper ends by heads 29, said rods passing throughopenings in the horizontal flanges of the upper frame member 5 andcarrying two springs 39 and 3|, one located above said horizontalflanges and the other below them, the lower end of the lower springresting upon a stop member 32 fastened to the bottom of said rods. Thevertical flanges of the upper frame member 5 lie within the down-'turned fiange'33 ofthe stationary outer casing in order to protect theoperator from the moving parts. Access to the rear suspension rodassemblies is effected through appropriate openings in the rear side ofthe maincasing;

The main frame is provided on its top with the top member 35, to whichis attached an angular member 36, which supports the drive casing 31attached therethrough through appropriate fasteners 38. As more clearlyshown inFig. 3; the drive member comprises a driven shaft 39 suitablyjournaled in the. drive casing as shown, said shaft being provided atits opposite ends with eccentric or cam portions 40 on which arejournaled' link members 4|, having bearings 42 at their lower endsadapted to have seated therein therod 43, which passes through openingsin U-shaped ears ,44, one leg of each ear being secured as by welding tothe upper frame member 5 of the vibrating unit 2. In assembling, thedrive mechanism may readilybe connected to the tray unit 2 by insertinga pin or the like in the openings 45 in the main casing opposite the endof the rod 43, then driving said and frame' member 6. their lower'endsbeing provided with enlarged heads 26' rigidly fixedthereon as bywelding and incapable of passing through said openings. These headsserve to limit the distance of the lower 'framernember 6 from the upperframe member .5. Also, permanently attached to thespacer rods '23 arestop members 2], each located a suflicient'distance below thecorresponding upper flange. of a spacer member 9 :to prevent its spacermember dropping below it, said stops being larger than the correspondingopenings in the flange of the spacer members. These stops are so locatedthat each spacer member will be retained in position sufliciently belowthe spacer member above it to permit the flanges 22 of the traystofreely'slide between them. As shown in the drawings, three such spacerrods are provided, one in the center 0f the rear of rod endwise in thedirection of the far side until the link 4| can drop to its verticalposition with its lower bearing in' line with the end of said rod thenperforming the same operation at the other side to permit lowering ofthe link 4| on that side, and finally centering said rod 43 by means ofsaid pin until complete connections are effected between said link andsaid rod.

The edges of the screen member 2| of the tray 20 are preferably providedwith a sheet metal binding with its outer edges turned in the form ofahook 46, as clearly shown in Fig. 5. Plate members 41 secured to thesides and ends of the tray'by bolts 48 and provided on their lower edgeswith hook members 49, to engage the hook members 46 onthe screen providea convenient means of tensioning the screen, when needed, thuspreventing sags and distortions of the screen members. The trays arebalanced sov that.each lwillbe of ..the-sa'me,.weighti and .thisisconvenientlyeeffected .bylQuse ,OifShiniS 2-50. of '.se-- '1lected'weight locatediunder-Qthe. nutsTBL-onsaich bolts, 1-,

In .the ,operationof the device, the lcrankimembers VI 9-,are2..operated rto. rotate.,the,,, rods. 9.; in the. nuts l3 fixed.to.the.lower.. frame. .Biuntil the: spacers 8 ..drop. on.theirrespective stops..21;.leav.-'- ing spaces, between adjacent. spacers;and ,the tops.

member- 5.. to ,permit. insertion ofzthe .traysj20,;1 10' their, flangesslidingover .the top flanges. of;- the. I spacers. into. the positionsshown inJFig- 1.. Thereupon,' theirods. 9. are turned'by' the. crankmember's. l9 the. oppositerdirection. tocliftl the;

lower,member;6.;until.al1 ofthe spacer..memberssandftrays.areprigidlyllocked tog'etherr Materiallc. having. beenfed,into. the. top, of; the. machine,-

the d iving,mechanism. is. .-then.set.inioperation which. operationmaygbeu observed. through. the-1 openfrontofthe' main casing. Whenthelscre'ene. g

action of the spacers, any sinsletray. maybe; 1

individually removed independently of any other tray, and also thevibrating unit may be operated with as many trays as may be desired. Thesprings and 3| cushion the vibration and the bearings I3 and I5 at thetop and bottom of the main casing maintain the rods 9 in verticalposition, thus insuring a balanced system, a minimum of vibration beingimparted to the outer frame.

While I have specifically described certain preferred forms of myinvention, it is obvious that it iscapable of embodiment in variousforms and modifications, and many features of my inven-' tion may beused without the conjoint use of other features, as conditions mayindicate to be top of said main frame for vertical reciprocatorymovement, means located at the top of said. main frame for verticallyreciprocating said unit, said unit comprising upper and lower framemembers, screen trays and tray spacer members alternately therebetween,and means for moving:

said upper and lower members toward each other to clamp said trays andtray'spacer members between them to form a rigid unit, or away from eachother to release said trays and spacers from said clamping engagement topermit removal of one or more of said trays, said means for moving saidupper and lower frames toward and I away from each other having verticalreciprocator y engagement with said stationary frame to compel verticalreciprocation of said unit.

2. A screening device comprising a main frame portion, a screen unitmounted for vertical reciprocatory movement in said main portion, saidunit comprising upper and lower frame members, screen trays and trayspacer members, each provided with flanges, between said upper and lowerframe members, the flanges on said trays lying between adjacent flangesof said spacer members, a binding rod passing through said upper andlower frame members and provided 7 above said upper frame member with afixed stop preventing upward movement thereon of said upper framemember; and provided in the region of said lower frame member with screwthreads carrying a stop nut in engagement with the. bottom side. of.said. lower frame, said. rod Y beings-rotatable in opposite. directionsto cause said nut .to bind together or loosen, respectively, themembers. of. said unit, the ends of. said rod' projecting throughbearings at the upper and. lower; ends. of said main frame tov permitthe unit to reciprocate. in vertical. direction, only.

' 3,; A screeningdevice comprising a main frame portion, .a screen unitmounted for vertical reciprocatory movement in said main portion, saidunit comprising. upper and lower frame members,.screen trays and trayspacer members, each provided with flanges, between said. upper andlowerfran e members, the flanges on said trays lying; between adjacentflanges of said spacer. members,v and a binding rod passing throughsaid-upperand lower. frame members and pro.-.

vided, above, said upper. frame member with 'a fixed stop preventinupward movement thereon of said upper framemember, and provided. in

the region of said lower frame member with.

screw threads carrying a stop nut in engagement wit eing rotatable inopposite directions to e ide ?e sv of a i t.

comprising upper and lower frame members, screen trays and tray spacermembers, each provided with flanges, between said upper and lower framemembers, the flanges on said trays lying between adjacent flanges ofsaid spacer members, and rods attached at one end to said upper framemember and passing freely through openings in the flanges of saidspacers and said lower frame member said rods being provided withadjustable means engaging aid lower frame member, which in one positionbinds said trays and spacers together and in another position releasessaid binding effect to permit individual removal of said trays and fixedstops on said rods,.each located sufiiciently below th flange of itscorrehaving upper and lower frame members, alternate screen trays andtray spacer members between said frame members, and means for bindingsaid parts rigidly together or for releasing them, rods attached at oneend to said upper frame member, and stops fixed at points on said rodsto hold said spacer members sufliciently apart when released to permitwithdrawal of any individual tray or trays.

6. A screening device comprising a screen unit having alternate screentray and tray spacer members, means operable to bind said memberstogether as a rigid unit, or to release them, and means to hold saidspacer members sufficiently apart when released to permit withdrawal ofany individual tray or trays.

7. A screening device comprising a screen unit having alternate screentrays'and tray spacers, said spacers being substantially U-shaped inhorizontal cross-section and provided with flanges at their top andbottom edges, said trays being provided with flanges at their top edges,normally adapted to lie between flanges of adjacent spacers, and meansfor clampin said tray and spacers together whereby a dust proof seal isprovided between said unit and the exterior thereof on two sides and therear.

h the bottom side of said lower frame, said s id 1 1. 1 .9.. d o her orl se s ew screeni dev ce. p is n a screen unit,

8. A screening device comprising 'a screen unit having alternate screentrays and'tray spacers,

said spacers being substantially U-shaped in horizontal cross-section,and means for clamping said trays and spacers together whereby a dustproof seal is provided between said unit and the exterior thereof on twosides, and the rear.

9. A screening device comprising a screen unit havin alternate screentrays and tray spacers of greater vertical height than said trays, saidspacers being substantially U-shaped in horizontal cross-section andprovided with flanges at their top and bottom edges, said trays beingprovided with flanges at their top edges, normally adapted to liebetween flanges of adjacent spacers, and means for clampingsaid traysand spacers together whereby a dust proof seal is provided between saidunit andthe exterior thereof on two sides and the rear,- and inspectionopenings are provided over the tops of said trays, at

the front.

and lower frame. members, the flanges on said trays-lying betweenadjacent flanges of said spacer members, a binding rod passing throughsaid upper and lower frame members and provided above said upper framemember with a fixed stop preventing upward movement thereon ofsaidupper'frame membenand provided in the region ofsaid lower framemember with screw threads carrying a stop nut in engagement with thebottom side of said lower frame, said rod being rotatable in oppositedirections to cause said nut to bind together or loosen, respectively,the members of said unit, the ends of said rod projecting throughbearings at the upper and lower ends of said main frame to permit theunit to reciprocate in vertical direction, only and other rods attachedat one end to said upper frame memberand passing freely through openingin the flanges of said spacers and said lower'frame member and fixedstops on said last mentioned rods, each located sufficiently below theflange of,its corresponding spacer to hold the same sufliciently farfrom its adjacent spacer to permit the tray whose flange liestherebetween to be readily slid'out of the unit. j

SETH J. GILSON.

